SPORES HYALINE. 



drying discolored and agglutinate. Spores ovate, or subglobose, 

 hyaline, transparent, smooth, 6-7 mic., with large guttae. 



European mycolpgists agree on Polyporus spumeus in the sense 

 of Fries at least. It is evidently a heart rot, and always comes from 

 decayed portions of living trees. In the park at Upsala it prefers the 

 maples; rarely we found it on poplar. It has never been observed by 

 me on elm, where Sowerby and Fries record it. In America, in the 

 East, it seems frequent on apple trees, and is one of the few fungi that 

 infect the apple tree stems. We have never collected it out West, but 

 have specimens. Fries refers it to Sowerby's figure (t. 211), and, 

 from Sowerby's remarks rather than from his figure, we think cor- 

 rectly. It first appears as a soft, white, rounded or amorphous mass, 

 but it is not strictly correct to state that "it oozes as a soft, frothy 

 mass." 



The spores, each with a large gutta, are characteristic, also the 

 incised, floccose surface such as shown in our figure 641, which disap- 

 pears in dried specimens. The pores and flesh both discolor in drying, 

 the pores slightly darker than the flesh. 



SPECIMENS. A number from Europe and three thick forms from United States. 



ILLUSTRATIONS. Two are cited, Sowerby 21 1 and Berkeley's Outlines, t. 16, fig. 4. Neither 

 well represent the plant, showing dark surface and tubes. The noticeable feature of the fresh, growing 

 plant is that it is pure white. 



Compare mollissimus. 



VAR. MALICOLUS. The usual American form of Polyporus spumeus is 

 thinner than the European plant and usually grows on the apple tree. The flesh is 

 usually less than 2 mm. thick, and the spores are smaller, measuring 4-5 mic. Other- 

 wise it is the same as European plant as to color, surface, appearance, pores and 

 peculiar, guttulate spores. It is the white species that occurs on the apple tree in 

 New England. It occurs less frequently further west, and on other hosts. It is the 

 basis of Polyporus galactinus of Murrill's work, a mistake, however, for it is quite 

 different from the true Polyporus galactinus. 



SPECIMENS. We have twenty collections from the United States, mostly from the New 

 England States, and a number where apple is stated to be the host, a few on chestnut. We do not 

 know this thin form in Europe. We have also three American collections with thick flesh correspond- 

 ing to the plant in Europe. 



POLYPORUS SPRAGUEL Pileus when growing, white, but 

 dried specimens are dirty white, or cinereous. Surface hard, rough, 

 uneven, with no distinct crust. Flesh white, drying white, hard, firm, 

 rigid. Pores small, round or angular, white, drying discolored, 

 cinereous. Spores subglobose hyaline, 4-5 mic. 



This is a rather frequent plant in the United States, and when 

 fresh is decidedly malodorous. It sometimes occurs in abundance on 

 beech, around Cincinnati, and is quite large a foot or more in diam- 

 eter. We have only found it on beech, but Murrill records it on oak 

 and chestnut. For years the plant was in our collection as Polyporus 

 foetidus, as we could get no name for it, every one to whom we sent it 

 calling it a different name. It is Polyporus epileucus of Morgan's 

 flora. Murrill was the first man to get it right in the United States, 

 and we first learned it from specimens that he had named. We after- 



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